Production of aniline black on textile fibers



Patented Dec. 17, 1929 warren stares raiser errica LOUIS AMEDE E LANTZ AND RONALD WATSON, F MANCHESTER, ENGLAND PRODUCTION OF ANILINE BLACK ON TEXTILE FIBERS No Drawing. Application filed July 18, 1927, Serial No. 206,789, and in Great Britain July 20, 1926.

. This invention relates to the production of aniline black on textile fibers, especially cotton, by the ferrocyanide process, and has for its object to provide an improved and simplified process for the rapid production of an ungreenable black.

We have found by research and experiment hat the formation of aniline black on textile fibers by the ferrocyanide process takes place the more rapidly and the more completely,

and that the black formed is the less greenable the higher the temperature applied in ageing. V1 e have further found that the best results are obtained by carrying out the process in two stages in the first of. which the fibers are subjected to a high temperature in the absence of steam.

Our invention comprises a process for the production of aniline black on textile fibers 2 in which the latter after being impregnated or printed with the usual mixture containing mainly aniline salt, alkali metal chlorate and alkali metal ferrocyanide, are subjected to a temperature of from 110 to 180 C. for a period of from 5 to 45 seconds in the absence of steam and then heated in the presence of steam for a period of from 15 seconds to one minute, the fibers being then washed in water or a weak alkiline solution.

3 I the application of our invention, the

fabric is impregnated or printed in the 01'- dinary manner with the usual mixture containing mainly aniline salt, alkali metal chlorate and alkali metal ferrocyanide and then dried. Thereafter it is passed through a heater (hereinafter termed a preheater) which may consist of steam, hot air or other heated chests arranged in close proximity to one another to provide a circuitous path between chests for the passage of the fabric.

There is no steam present within the heater and there is little or noair flow therein. The

temperature to which the fabric is subjected is between 110 and 180 C. and the period of such high heattreatment is between 5 and seconds. The fabric is now passed into an ordinary rapid steam ager where it is subjected to the action of steam for a period of from 15 seconds to one minute. The temperature within the ager may be such as is normally used, that is, between 100 and 105 (3., but temperatures up to 180 C. may be employed. The after treatment consists in simply washing the fabric inwater or in a weak alkaline solution. The fabric may be printed either before or after'the impregnation or printing before referred towith white or coloured resists to produce desired patterns.

The time taken duri'ngthe' high heat treatment of the fabric without steam and during the steam treatment may be varied considerably within the limits specified, depending on the temperature applied, the composition of the paddin liquor and the machinery used, but the operation should not be prolonged beyond the point where the desired black has been obtained.

By the employment of a temperature of from 110 to 180 C. immediately before ageing and optionally also during ageing, not only does the formation of the aniline black take place more rapidly but the loss of aniline due to evaporation which normally occurs is avoided, and the black produced is superior in quality to that ordinarily obtained and is absolutely ungreenable, even'without having been after-treated with the usual oxidizing agents, such aschromate. A further advantage of our process lies in a reduction of the tendering of vegetable fibers, which always accompanies the formation of aniline black under ordinary ageing conditions. The aforementioned advantages derived from our invention are particularly marked at the higher temperatures, say between 140 and 160 C., where the total time of treatment can be shortened to 30 to 45 seconds instead of 1 to 2 minutes as usual in ordinary agers.

The preheater and ager may be arranged in close proximity to one another or may constitute two compartments of a single machine. The preheater may have ventilating apertures with flaps or valves thereon to regulate or allow the flow of air through the preheater.

What we claim is 1. A process for the production of aniline black on textile fibers in which the latter after being treated with the usual mixture containing mainly aniline salt, alkali metal chlorate and alkali metal ferrocyanide and dried in the usual manner, are subjected for a short period to a temperature of from 110 to 180 C. in the absence of steam and then to a steaming operation, as set forth.

2. A process for the production of aniline black on textile fibers in Which the latter after being treated With the usual mixture containing mainly aniline salt,. alkali metal chlorate and alkali metal ferrocyanide, is dried, subjected to a temperature of from 110 to 180 (1, for a period of from 5 to 45 seconds in the absence of steam and then to a temperature of from 100 to 180 C. in the presence of steam for from 15 seconds to one minute, the fibers being thereafter Washed as set forth.

In testimony whereof We have signed our 29 names to this specification.

LOUIS AMEDEE LANTZ. RONALD lVATSON. 

